The present invention relates to shut-off valves for supply cylinders of pressurized gas, and more specifically to a button-controlled valve which operates to provide fluid shut-off, manually-controlled fluid flow, excess flow control, and pressure-regulator flow control, all within a safety-oriented housing that attaches directly to a supply cylinder of gas under pressure.
Certain known valves for controlling the flow of gas under pressure rely upon internal valve elements which are controlled externally via a rotating valve stem, or the like, and such valve stems require rotating or sliding seals to prevent escape of the fluid under pressure around the valve stem. Such manually-operated valves are widely used as the main shut-off valve on top of a supply cylinder of fluid under pressure. However, recent developments of the wide scale use of highly-toxic gases in the semiconductor industry have prompted careful review of the poor safety features associated with the conventional shut-off valve which is based upon a rotating seal that is highly subject to failure and which requires many manual turning strokes to shut off the flow of pressurized gas from the cylinder. Such valves are unsuitable for quickly controlling emergency conditions of fire or toxic gas leaks, or the like. Also, these shut-off valves are usually heavily cluttered with excess-flow control valves, pressure regulators, and the like, connected thereto which further inhibits convenient manual control of such conventional valves. Also, high-pressure connections associated with components that attach to the main shut-off valve are highly vulnerable to leak and rupture due to the cylinder falling over, or the exposed components being banged or the fluid lines connected thereto being pulled.